Durable response after interruption of nivolumab in patients with metastatic renal cell carcinoma: Is renal toxicity a marker to predict the benefit of nivolumab?

INTRODUCTION: Nivolumab is a human IgG4 programmed death-1 immune checkpoint inhibitor antibody. Immune-related toxicity may be associated with higher response even after interruption of nivolumab. CASE REPORT: We reported a case diagnosed with metastatic clear cell renal cell carcinoma and treated with nivolumab as fourth-line therapy. Although nivolumab treatment was stopped after two cycles due to grade 3 renal toxicity, progression-free survival rates of 11 months, that is quite a long time for fourth-line treatment of renal cell carcinoma was observed. MANAGEMENT AND OUTCOME: Therefore, we speculate that when renal toxicity develops, response may continue even after interruption of nivolumab in renal cell carcinoma. DISCUSSION: Nivolumab was approved to be used for second-line treatment of renal cell carcinoma with 4.6 months of median progression-free survival benefit. Higher immune-related toxicity can produce higher efficacy for some instances such as malignant melanoma, lung cancer, and renal cell carcinoma. Renal disturbance during nivolumab treatment is extremely rare, and there are no data on survival after interruption due to renal toxicity of nivolumab without further treatment in renal cell carcinoma. In the present case, we obtained long duration of stable disease, with two cycles of nivolumab after the development of nephrotoxicity. Close follow-up without any treatment until progression may be a treatment choice, because nephrotoxicity can be a sign of benefit and durable response to nivolumab.